West Nile virus linked with U.S. orchards

Researchers have linked mosquitoes, which populate orchards and vineyards, as areas with a greater prevalence of West Nile virus, in the U.S. This relates to the way mosquitoes spread the virus to birds, horses and people.

The research has looked at the relationship between land use and the virus's activity in key hosts, especially looking at how the disease moves across the landscape. For this the scientists evaluated how three land-use types (orchards, vegetable/forage crops, natural) and two climatic variables (temperature, precipitation) This showed that agricultural areas have seen higher percentages of infected people.

The data indicated that habitats with high instances of the disease in horses and birds also have significantly more mosquitoes. From this, the researchers speculate that mosquitoes are drawn to orchards for plant nectar during flowering.

West Nile virus was first reported in New York in 1999 and since then it has reached across most of the U.S. In many cases the disease causes fever, headache, body aches and, in some cases, a skin rash and swollen lymph glands. The outcomes of the study may help to bring the disease under control.